/* 
 * [New BSD License (BSD 3-Clause License)]
 * Copyright (c) 2012, Max Bechtold
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 * 
 *     - Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     - Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     - Neither the name of the Rel2Xml Project nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
package maxbe.rel2xml.generator.docs.constraints;

import java.util.ArrayList;
import java.util.Arrays;
import java.util.Collections;
import java.util.List;

import maxbe.rel2xml.generator.docs.DataType;

/**
 * Represents SQL null values. For ease of implementation, these are represented
 * by Java nulls.
 * 
 * @author Max Bechtold
 * 
 */
public class Nulls implements ValueConstructor {

	private static final List<DataType> types;

	static {
		types = new ArrayList<DataType>(Arrays.asList(DataType.values()));
	}

	@Override
	public boolean lengthVaries() {
		return false;
	}

	@Override
	public int getLength() {
		return -1;
	}

	@Override
	public int getSubLength() {
		return -1;
	}

	@Override
	public boolean needsAnnounce() {
		return false;
	}

	@Override
	public void announce(int number) {
		// Not needed
	}

	@Override
	public List<DataType> getSupportedDataTypes() {
		return types;
	}

	@Override
	public void mark(int number) {
		// Not needed
	}

	@Override
	public String next() {
		return null;
	}

	@Override
	public List<String> next(int number) {
		return Collections.nCopies(number, null);
	}

	@Override
	public String toString() {
		return "null";
	}

}
